Drug approvals in oncology often build on treatment effects by adding drugs to current regimens or by combining investigational drug products in a combination regimen, creating new regimens with greater efficacy. Traditionally, applicants have not requested changes to the labeling of a previously approved drug to describe how to use that drug in a new regimen (cross labeling). However, there has recently been an increasing number of applications that have proposed cross labeling for oncology drug combination regimens. The purpose of this guidance is to describe FDA’s current recommendations about including relevant information in labeling for oncology drugs approved for use in a combination regimen, including important considerations for cross labeling of these drugs. This guidance does not address all issues that might arise relating to labeling for oncology drugs for use in a combination regimen. Applicants proposing cross labeling for oncology drug combination regimens should contact the review division for information on cross labeling of their individual products.